Kosmos 186 and Kosmos 188 were two uncrewed Soviet Union spacecrafts that made the first fully automated space docking in the history of space exploration on 30 October 1967. Kosmos 186 was launched first on October 27, 1967, followed by Kosmos 188 three days later. With Kosmos 186 taking the active role in the docking, the two craft docked just 62 minutes after the launch of Kosmos 188, the passive target spacecraft. Mutual search, approach, mooring, and docking were automatically performed by the IGLA-system onboard Kosmos 186. After 3.5 hours of joint flight, the spacecrafts parted on a command sent from the Earth and continued to orbit separately. Both made a soft landing in a predetermined region of the Soviet Union — Kosmos 186 on 31 October 1967 and Kosmos 188 on 2 November 1967.
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| Kosmos 186 launch cover with Tartu postmark on October 28, 1967. |
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| Kosmos 188 landing cover with Tartu postmark on November 3, 1967. |
The automatic docking mission demonstrated a new capability for the Soviet Union that proved valuable to their subsequent Salyut and Mir space station programs. This mission also proved that it's possible to launch smaller parts and assemble them in space, thus eliminating the need for exceedingly large rockets for larger undertakings like a space station.
(Reference from
Kosmos 186 and Kosmos 188)
